Earth Commission report says planet has breached 7 of 8 safe boundaries
Listen 5 min Comment on this story Comment Gift Article Share
A team of top scientists says that it has assessed the planet’s health against eight key thresholds needed to protect life on Earth and that human activities have led to seven of the eight of the boundaries already being breached. Wp Get the full experience. Choose your plan ArrowRight “The window is rapidly shutting; we’re very close to irreversible tipping points,” Johan Rockström, a director at the Potsdam Institute for Climate Impact Research and the lead author of the study published this week, said in a telephone interview. Rockström has described the report as the first time that quantifiable boundaries have been presented in this way “to assess the state of our planetary health,” measuring not only the stability of Earth’s ecosystems, but also assessing human well-being and equity.
The research conducted by the Earth Commission, a team of dozens of scientists representing leading global research institutions, said the eight areas measured were: climate change; aerosols (air pollution); surface water; groundwater; nitrogen fertilizer; phosphorus fertilizer; whether natural ecosystems remained largely intact; and the functional integrity of all ecosystems.
Advertisement
The peer-reviewed study, published in Nature, assessed each area against two thresholds: whether it remained “safe” — that is, within the levels needed so the Earth’s systems can support humans and other living organisms — and whether the levels could ensure justice between species, current and future generations, and between countries and communities.
It defined “just” thresholds as boundaries that minimize “exposure to significant harm” — including “substantial loss of life, livelihood and income, loss of access to nature’s contributions to people, loss of land, chronic disease, injury, malnutrition and displacement” — to countries, communities, or individuals. In some areas, including groundwater and surface water thresholds, the “safe” and “just” thresholds are the same, while for others, climate among them, the “just” threshold is more stringent than the “safe” threshold.
The scientists describe the eight boundaries as “hard limits.”
Advertisement
“Even temporary overshooting of some of the boundaries can permanently damage the planet’s critical systems, causing irreparable harm to life,” they wrote.
Across all areas, the situation was “quite concerning,” Rockström said, explaining that the effects of breaching these limits are already visible.
“We get more extreme events, more droughts, more floods, more food insecurity, more ecosystem collapse, and then loss of fish stocks and destruction of coral reef systems, livelihoods for 500 million people,” he said, citing the devastating floods in Pakistan last year as “an example of being outside of a safe and just climate.”
The success in creating limits for climate change showed the need for similar targets for other factors affecting the planet’s health, according to Rockström — and the eight indicators were “designed as far as possible to be implementable at the local level.”
Advertisement
The report said that Earth had already surpassed both safe and just boundaries in most areas it measured: Surface water flows were being altered too much, causing damage to ecosystems, groundwater was being used up more quickly than it could be replaced, and nitrogen and phosphorus fertilizers, with their damaging effects on water and air pollution, were being used at levels far above what is recommended.
The two biosphere boundaries also had been breached as the percentage of natural ecosystems remaining in the world, in natural areas and working landscapes, are lower than the levels needed to protect humans and other species, the report said.
For climate change, the planet had surpassed the just, but not the safe, boundaries — meaning that the temperature rise of 1 degree Celsius (1.8 degrees Fahrenheit) from preindustrial levels had been breached and had led to harm to human life, but did not yet threaten planetary stability. The report identified the safe limit for climate change as 1.5 degrees Celsius (2.7 Fahrenheit) above preindustrial levels — the target of the Paris climate accord. In March, however, a U.N. report warned that the world was likely to pass this figure early in the next decade.
Advertisement
Aerosols were the only area in which a breach of safe or just measures had not occurred — although the commission warned that “areas of high air pollution remained” and that “no level of air pollution can be called absolutely safe from a health perspective.” It also noted the potential impact of air pollution in one hemisphere of the world on rainfall and monsoon in the other, as well as the “significant harm” to human health, including respiratory and heart problems, and premature death.
Despite the worrying findings, the scientists are keen to stress that it is not too late for Earth, and they hope their report will galvanize governments and companies to make changes.
“There’s also a lot of evidence that if we reduce the pressure and start really regenerating and managing nature, particularly transitioning into sustainable food systems, then we can build back the capacity of these systems to both stabilize climate but also to deliver good livelihoods,” Rockström said. “So, overall, we see a possibility here of transforming back, but it has to go very, very fast.”
While the Earth Commission’s report is focused on global initiatives, experts say there also are practical steps individuals can take to help address some of the threats facing the planet, including changing eating and shopping habits, and embracing renewable energy and public transport.
GiftOutline Gift Article
Source: The Washington Post
